Resolving Error 0x800f0929: Installing .NET Framework 3.5 on Windows Server 2012

To address error code 0x800f0929 while attempting to install .NET Framework 3.5 on Windows Server 2012, follow these steps:

1. Verify .NET Framework 3.5 installation status: Navigate to Control Panel > Programs and Features > Turn Windows features on or off. Check if .NET Framework 3.5 is already enabled.
2. Implement the DISM tool: Launch Command Prompt with administrative privileges and enter: DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs (substitute D:\ for your actual Windows Server 2012 installation media drive letter). This will initiate the .NET Framework 3.5 setup from your installation media.
3. Run the Windows Update Troubleshooter: Access Control Panel > Troubleshooting > System and Security > Fix problems with Windows Update. Execute the troubleshooter and address any detected Windows Update issues.
4. Manually download and install .NET Framework 3.5: Visit the Microsoft Download Center, download the .NET Framework 3.5 installer, and follow the instructions provided to complete the installation.
5. Inspect for relevant updates: Open Control Panel > Windows Update and search for new updates. Apply any updates pertinent to .NET Framework or Windows Server 2012.